[HbA1c--the gold standard in the assessment of diabetes treatment?]

Abstract

HbA1c is an important measure in monitoring treatment and management decisions in diabetic patients. It reflects the mean blood glucose level during the preceding 6 to 8 weeks. But this is true only for the population as a whole, not the individual patient. Differences between blood glucose and HbA1c values must be analysed precisely, because it is subject to numerous factors. HbA1c cannot replace blood glucose measurements for immediately assessing glucose metabolism and recognizing acute metabolic abnormalities. The mean HbA1c level predicts potential diabetic complications and is closely correlated with clinical angiopathic end-points. The quality of metabolic regulation can be assessed from HbA1c and blood glucose levels at defined times. But because of the numerous influencing factors HbA1c can be used as gold standard only with limitations. Developments, as in Great Britain and the USA, which take HbA1c as relevant basis for treatment ("pay for performance"), lead in a completely wrong direction and contribute neither to the validity of documented values in structured therapeutic programmes nor do they stimulate improvement in the overall management of diabetes. The quality of metabolic control should be determined entirely within the therapeutic target worked out together with the patient.